Re: What is with the pickiness of the iPad pro's architecture?

[Sean McBride]

On Tue, 18 Oct 2016 12:04:56 -0700, Jens Alfke said:

>> There is a compiler warning that can be turned on for this (one of the
>“mismatched selector” warnings), but in my experience there are too many
>false negatives *and* false positives, making the warning useless.
>
>“Strict Selector Matching”? I agree, it’s infeasible to use that in any
>real-world code.

It used to work reasonably, but regressed in Xcode 7 (), and 
in Xcode 8 it works well again.  I'm able to have it on in my largish Obj-C 
codebase with no warnings.

You might want to try it again.

Cheers,

-- 

Sean McBride, B. Eng s...@rogue-research.com
Rogue Researchwww.rogue-research.com 
Mac Software Developer  Montréal, Québec, Canada

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Re: What is with the pickiness of the iPad pro's architecture?

[Jens Alfke]

> On Oct 18, 2016, at 11:34 AM, Quincey Morris 
>  wrote:
> 
> There is a compiler warning that can be turned on for this (one of the 
> “mismatched selector” warnings), but in my experience there are too many 
> false negatives *and* false positives, making the warning useless.

“Strict Selector Matching”? I agree, it’s infeasible to use that in any 
real-world code. However, there is a static analyzer flag “Method Signatures 
Mismatch” that IIRC does this same type of checking without the false alarms.

—Jens ___
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Re: What is with the pickiness of the iPad pro's architecture?

[Patrick J. Collins]

> > CGFloat is a float, yet it returns 0??? WTF?
>
> It isn’t a float. What you’re seeing in the debugger *confirms* that CGFloat 
> is 64 bits.

Hmm.. I guess I don't understand that then.  My logic was because
casting as a double returns the expected value, and casting as a CGFloat
does not, that it couldn't be a double...

> You’re also confusing the concepts of a cast as a value conversion and a cast 
> as a re-interpretation of the type of variable (which re-interprets the 
> underlying memory bits), and that’s what Greg was trying to alert you to:
>
> >> The debugger console may interpret it
> >> differently (using the cast as a hint of the correct return type,
> >> rather than a conversion of the real return type).

I see...

> There’s something else going on here. You might want to show some
> code, including the declaration of (say) your “laserXOffset” property,
> and the line where you set the scale.

The scale code I discovered was breaking due to a protocol's interface
being used on a class that defined a different type.

So, it went like this:

@protocol MenuInteractable 

-(void)setScale:(CGFloat)scale;
// other stuff

@end

 Meanwhile a class in the game library:

@interface CCNode : NSObject
@property(nonatomic,readwrite,assign) float scale;
// other stuff
@end

so I had a class inherit from that:

@interface MenuItem : CCNode 
@end

.. and an object using that was doing:

id item = menuItem;
item.scale = 1.0f;

//

And then when I'd get into the setter it would be assigning the value 0.

Once I changed the MenuInteractable property to:

-(void)setScale:(float)scale;

Then all my sprites were back..  I didn't even realize float was
what the actual real class was using, I assumed it was CGFloat and
that's why I put it on that protocol.  And like I said, on my iPhone 6
and iPad3, it was totally ok with how that was.

...

Sorry for my temper fit.  Sometimes I go argghhh when things make no
sense, and I am afraid I am going to need to go out and buy an iPhone7
now because I have no idea whether there's something else that's going
to behave differently on it compared to all these other devices.

Patrick J. Collins
http://collinatorstudios.com


On Tue, 18 Oct 2016, Quincey Morris wrote:

> On Oct 18, 2016, at 00:04 , Patrick J. Collins 
>  wrote:
> >
> >> Is your process 64-bit or 32-bit? CGFloat is float in 32-bit processes and 
> >> double in 64-bit processes.
> >
> > I'm not sure what you mean?  The app is intended to work on both 32-bit
> > and 64-bit architectures.  My iPad3 is a 32-bit device, and my iPhone-6
> > is a 64-bit device.  On both of those devices everything is fine and
> > casting 1.0 as either a CGFloat or float with both result in 1.0 (as
> > expected).  On the iPad pro, this bogus behavior happens where 1.0 cast
> > as a CGFloat becomes 0.
>
> You’re having a little temper fit here, which is fine by me except that it’s 
> leading you into technical incorrectness, not to mention contradicting 
> yourself. You said:
>
> >  (lldb) expr (float)[self.fireable laserXOffset]
> >  (float) $11 = 0
> >  (lldb) expr (CGFloat)[self.fireable laserXOffset]
> >  (CGFloat) $12 = 400
>
> >  (lldb) expr (double)[self.fireable laserXOffset]
> >  (double) $15 = 400
>
>
> That is, according to you, casting *as a float* produces 0, and casting as 
> CGFloat or double [identical in iPad Pro as in iPhone 6/7] produce the same 
> non-zero value. Somehow, though, you’ve mixed this up:
>
>
> So, back to your actual problem:
>
> > Yes, when I first tried my game on the iPad pro, a huge percentage of my
> > sprites were invisible, and it was because their scale was being set to
> > 1.0 as CGFloats, which was turning into 0.  So I had to make sure all
> > the places where scale was being set was using an actual float type.
>
>
> > I feel like I should just sed -i my entire
> > project and turn all CGFloats into floats... But I am not sure if that's
> > really a good idea.
>
> No, that’s a really terrible idea. Voodoo solutions always are.
>
>
>
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